Purpose
C-arm flat-detector computer tomography (FD-CT) [1] opens new opportunities for navigation, guidance and control and for interventionalradiology.Within the framework of OrthoMIT (http://www.orthomit.de), a flexible and vendor-independent image reconstruction station for FD-CT was developed by VAMP GmbH and theInstitute of Medical Physics, both Erlangen, Germany. The aims and challenges are to: Develop a reconstruction platform for intraoperative FD-CT with "realtime" capability. Integrate the system to medical environment (DICOM, PACS, ...). Improve image quality by including advanced correction steps. The correction steps include: Misalignment correction Detruncation Scatter...
Methods and Materials
A CT equipmentFor the measurements, a multi-axis C-arm Artis prototype (Siemens Healthcare, Forchheim, Germany) has been used. It is equipped with a large flat-panel detector of 40.0 x 30.0 cm² size.B Reconstruction platform Modular design. Standard Feldkamp (FDK) algorithm. Process flat-detector raw-data formats from various FD-CT manufacturers. Partial scan reconstruction (Parker weighting) that needs only a scan over 180° plus fan-angle. Real-to-ideal geometry rebinning to ensure the portability between different FD-systems. Analytic water precorrection (beam-hardening correction). Convolution with various selectable kernels. Up to 1024³ voxels...
Results
The reconstruction platform provides a wide range of artifact corrections. Advanced correction steps significantly improve the image quality.A fast and extensible system has been designed using client-server architecture and a vendor-independent modular concept. DICOM services provide integration into medical workflow and additionalapplications, e.g. navigation.Image reconstruction times of 1-2 min for a 512³ voxel volume from about 500 projections were achieved on a standard PC hardware including region ofinterest reconstruction. The built-in DICOM services provide a seamless integration into the clinical and/or intraoperative workflow in a...
Conclusions
The developed vendor-independent reconstruction platform meets the need for an efficient, fast and extensible system that can be used for multipleapplications in the intraoperative FD-CT workflow. It has been developed within the framework of OrthoMIT (http://www.orthomit.de). Further hardware acceleration is easily possible using modularconcepts or graphics processing units (GPUs).